1. Field of the Invention
The present invention relates to an electric coupling device, to an electric circuit provided with such an electric coupling device and to methods for connecting, disconnecting and/or limiting the current in an electric circuit.
2. Discussion of the Background
Considerable advantages could be gained if the short-circuiting current in an electric power system could be limited. No expedient current limiter exists today apart from fuses. Increased demands on the quality of electric power accentuates the need for current limiters. Current limiters based on electric arcs, resonance circuits or semiconductors are usually so bulky and expensive that they cannot be considered for other than extremely specialised purposes.
Various types of surge arresters have long been used to limit the voltage in electrical systems and providing a current limiter which, similar, is inexpensive, small and simple would satisfy an urgent need. It is desirable for the voltage over the current limiter to be dependent only on the current strength.
An equivalent need also exists in connection with connecting and disconnecting the load current in an electric circuit and it would be desirable to achieve this without electric arcs and with more efficient attenuation of oscillations in the system.